An accident waiting to happen

[Chocks Wahay]

Flew in to a small regional airfield at the weekend - nice little airport, 850m of tarmac, nice bar, friendly staff etc. The only problem was the integration of helicopter training with fixed wing flights. The field is very limited for space, and students have to use the airfield to learn & practice hovering and autorotations etc. The only space available to them is the grass at the side of the runway, and so you have students hovering and taxying along the side of the runway, literally a few feet from the active runway, as other aircraft are landing and taking off. It wouldn't be quite so bad if they at least used the far end of the runway, but they come right to the threshold of the active while aircraft are landing.

Does this sort of thing go on anywhere else? I fully understand the difficulties of integrating heli and fixed wing ops, and can appreciate the commercial concerns, but it looks like an accident waiting to happen imho - all it would take is a gust of wind to blow a helicopter into the path of a landing or departing aircraft.

[Final 3 Greens]

Don't know what sort of helicopters, but the turbulence from their downdraught could be a bit dodgy if it gets blown across the runway by the prevailing winds.

[hoverbover]

Hello Chocks Wahay,

Yes I think youll find this practice does go on at quite a few airfields in the UK.

I guess that you have not done any helicopter flying? Please accept my appologies if you have! If you have you will have seen that a gust of wind sufficient to blow a helicopter ACROSS the runway, would make any landing by a fixed wing very interesting to say the least.

3 Greens has a good point about the downwash though, how close were they to the active? I fly into airfields all over the country, and on the whole fixed and rotary seem to work very well together. I must admit that looking from a fixed wing perspective, helicopters seem to do strange things but , once you can see from the rotary side as well, it makes far more sense.

I would be interested to know which airfield it was. (Sounds a bit like Shobdon or Welshpool)

Regards

Hover Bover

[ 30 July 2001: Message edited by: hoverbover ]

[Wee Weasley Welshman]

Not Welshpool.

WWW

[Spoonbill]

I assume that this is a CAA licensed airfield, and I'm suprised that they haven't jumped on it.
We have helicopter training in similar circumstances, but it is done on a parallell taxiway which is separated from the main runway by around 600m.
At another airfield which I use, there is helicopter training adjacent to the runway, but simultaneous use is not permitted, (ie. if an aircraft is touching down, the helicopter must remain airborne).
It sounds pretty irresponsible to allow the 2 types to mix so closely.

[hoverbover]

Hi WWW,
Only thought of Welshpool because of its length and lack of space! hehe.

Regards

Hover Bover

[Deeko01]

Sounds like Cumbernauld to me!!!

Don't think its as bad as you make out though, not if everyone uses good airmanship.

[Whirlybird]

I don't think it's Shobdon. They have separate parallel grass runways for use by helicopters, microlights, and gliders. It's crowded, but not that close to the hard runway. I'm still wondering where it is too.

[Kermit 180]

It happens at a lot of airfields. As for too close with rotor wash, the rotorheads tell me 3 times the diameter of the blades is a good separation to avoid being blown over. They'd surely be further away from the runway than that.

Kermie :)

[Chocks Wahay]

Hoverbover - you're quite right I haven't done any rotary flying (as pilot anyway), so I take your point about crosswinds. Some of the students seemed very wobbly, and certainly didn't hover taxi in straight lines. It wasn't that windy, so I assumed helos were perhaps more prone to being blown about than fixed wing. The R22 isn't exactly a heavyweight machine.

Spoonbill - yes it is licenced, it has to be to provide training. They are very tight for space, and I understand students have to used a licenced aerodrome for hover-taxying and autorotations.

Kermit 180 - not sure how many rotor-lengths away they are, but space on the northside of the runway is very limited. I got the most horrendous float & bounce on landing, and was on the point of going-around. I don't claim to be any great shakes as a pilot, but I haven't had that on previous landings (including an hour before at the same field in very similar weather) or subsequent ones. We all make mistakes, and being distracted by a hovering helo at the threshold taking off as I was about to flare doesn't help of course.

Deeko01 - I thought I was over-reacting as well, but other pilots I have spoken to since have similar concerns.

It's probably different for pilots based there, who have an idea of what the helo's are up to, but as a visitor I was in the dark. I had phoned for a weather & approach briefing before leaving, so that would be the time to warn people about helo ops I think. Ultimately of course it is my decision as P1 to land or go-around.

[Vfrpilotpb]

Hi Chocks,
The R22 rotor is approx 25ft dia so X 3 would be about 75ft, but the wash from a Robbie wouldn't ruffle any feathers at that distance, also the wind would have to be blowing at about 18/plus Knts to even start to push the robbie into your way, as you have not flown R22 they always weathercock into wind, and if being flown by a low time Student would not be out in anything greater than 8/10 KntAbs max wind unless with a FI or CFI, normally also when on your approach to the field did the ATC not warn you of Heli movements, if they did when you acknowledged that they would then tell the Heli of your imminent aproach/depart which they(the heli) would then have to acknowledge, from my past experience on a mixed training field mixed with commercial departures and landings the Heli would either Hover and wait for your move to start/finish or would land and wait with Rotors running, no big problem either way as long as you are all aware of each other.
My Regards :)

[Chocks Wahay]

Vfrpilotpb - I spoke to my passenger last night, who reckoned that the helicopters are considerably less than a runway's width (23m) away from the runway. Subtract the distance to the rotor tips, and that's too close in my book.

I appreciate what you're saying about mixed ops, and I could see it might work on a field with full ATC but as the field is air/ground only you are relying on the other pilot(s) seeing you - if he's a low hours student trying to hover his attention may well understandably be elsewhere.

[Multp]

I think you'll find that CAA Aerodrome Standards Division lays down minimum lateral separation criteria for simultaneous F/W and rotary movements, but these criteria do leave a certain leeway for interpretation. I can think of one airfield where they were quite strictly applied, although up until then the common-sense approach (no pun intended) had worked well for many years without incident, other than the occasional straying of aircraft off their respective centrelines during climb-out.
As for downwash effects, the R22 or similar sized Schweizer/Hughes helos are unlikely to affect manned light aeroplanes: not enough to cause them to do anything dramatic, like overturn. An unmanned aicraft may well have its control surfaces buffeted about, possibly resulting in damage. Nevertheless, a light aeroplane manned or unmanned should be avoided by as great a margin as possible: certainly at least one rotor span. Microlights should be given a very wide berth!

[Vfrpilotpb]

Hi Chocks,
Sorry to be a pain but you state " Air ground only" I may be wrong but that what you describe cannot be legal, for I am sure it has to be a fully ATC'd Airfield to allow any sort of tutorage ( as I said I could be wrong for cannot find my book for the ref)
But also yes you are correct and the 23 metre's is a little on the near to God am I syndrome!!
My Regards :eek: :eek:

[hoverbover]

Hi Chock's

A Helicopter is at its most unstable when it is in a Hover in ground effect(close to the ground) as soon as you transition into forward flight things become much more dignified!

The reason they are more unstable in the IGE hover is that the helicopters downwash is creating a cushion that the helicopter sits on, so hte heli uses less power in the hover, the problem is the cushion is like a dome so the helicopter is continually trying to fall off the cushion, hence the reason people find it more difficult to hover when they are learning in no wind conditions, if there is a breeze the heli is far more stable as it is not now sitting ontop of the dome but upwind of it.So effectively it has fallen off already!!!

Why this boring explanation, well in a no wind hover ,air from the cushion will move out from the helicopter in 360 degrees, and then will very quickly dissipate, especially in th case of light training helis, the heavier the helicopter the more forcefull the downwash. But if there is a wind the downwash from the helicopter will be far more concentrated, and will be pushed downwind from the helicopter, hence a heli pilot should give more care as to what is DOWNWIND of them, not upwind.

Why not try a flight sometime, having myself flown fixed wing for 10 years before going rotary wing , Im sure youll enjoy the experience, even if it is only a trial lesson.

VFR, I think the airfield needs to be licensed to perform training , so as long as it is licensed air/ground is OK

Regards

Hover Bover

[Vfrpilotpb]

Hover Hi Good morning,
Yes I was wrong, dont know why I thought that, possibly getting some rule mixed up in the old grey matter,
Chocks, yesterday I played about a little( just a turn of phrase) with a R22 in nil wind, in particular I was watching the ability of certain parameters when hovering and taking off, it seemed to me and the FI check pilot who I took with me that the Grass was disturbed up to about 20 feet on either side of us, bear in mind that was in Nil wind, so in theory that would give a total diameter of about 40/45 feet of disturbed air, but I stood on the loop and watched a partially loaded Dauphin take of and from about 100 feet from his rotors it was very windy obvious his greater power caused the greater downwash, hope that give's you some help.
:D

[VeeAny]

I did most of R22 training at Blackpool where ATC regularly mixed F/W and Heli traffic and were very good at it. The only time I had cause for concern was when a low time fixed wing guy did what he was taught, rather than what he was told and nearly flew straight through me at 50ft AGL when I was cleared to land (he landed and I had to go around from a very unusual attitude).

There a lot of small airfields out there that either don't understand helicopters or (perhaps as in the case or A/G stations) can't do anything with them. We are expected to join as fixed wing traffic would and pretty much get in everyones way, churning up the air as we go.

The places that are most used to Helis generally seperate the two quite well and everyone is happy.

There are obviously some not so switched on operators who are out purley for profit and employ people who don't seem to have any commons sense.

Perhaps I have missed it in previous posts, but would it be wrong to say which airfield your incident occured at (not trying to point the finger) just to give the guys concerned chance to put their case across.

I know when I am operating on airfield I always end up watching landing traffic and actually pointing the nose of the machine at it, just to keep an eye on it; after all what happens if a tyre bursts on landing and half a ton of metal decides to come and hunt you out from behind with no warning (unlikely I know).

I completely agree with the guys who say that wind strength enough to upset a robbo if crosswind to the landing runway would make the f/w pilots task more difficult at that moment.

Cheers

V. :)

[Chocks Wahay]

Some good points made in the last few posts, and interesting info about heli ops & techniques that I wasn't aware of being a fixed wing pilot.

The airfield in question is Cumbernauld, I didn't initially name it as I didn't want to appear to be getting at them, it was more of a point about mixed ops in general.

I'm sure it is possible to mix heli and fixed wing ops in most places, however the airfield in question is very tight for space. The helicopters (more than one, so I assume it's standard practice there) are never far from the runway (because there isn't space) - often close enough that the rotor tips are almost over the edge of the runway. Add in low hours students learning to hover and it doesn't look good.

Call me a wimp, but I just don't think there's enough space for this type of activity. As P1 I could elect to go around of course, but if the heli-guy is on an hour's lesson you could have a long wait for the runway to clear. Anyone working / based at Cumbernauld care to comment?

[Zlin526]

vfrpilotpb, you are wrong. A licensed airfield doesn't have to have a full ATC service. A local field has an A/G service, with lots of different aviation activity including parachuting, Whirly & noisy things, aerobatics and balloons all exisiting in complete harmony together with flight training. The only thing it doesnt have is gyrocopters, thank god! :D

[Floppy Link]

Cumbernauld is also home to PDG Helicopters who fly much heavier stuff than the R22 and R44 of the school there. Observation by our spy shows that PDG are very aware of the effect that their bigger downwash can have on light aircraft, always keeping a good lookout and landing on the grass if there is going to be a conflict (Downwash is minimal when the rotor disc is not having to support the aircraft.) Having said that it might be disconcerting to see 4 helicopters in the circuit...
Chocks were you in a Streak Shadow? If so you would be even more susceptible to adverse effects from the Robinson. Landing slightly long, beyond any anticipated downwash downwind of the helicopter, might be an idea. Better to have a slight backtrack to the turnoff than to have a "hairy :eek: moment".
I don't work there, I'm not an instructor (either H or A) but I would have thought that hover practice was limited to 10 minutes or so at the end of each flight as it is rather tiring for the new helicopter pilot. That's how the Queen taught me to hover a wee while ago. Our spy says that the hover practise is usually carried out at the upwind end of the runway.
But Pilot's Where to Fly guide does list Scotia Helicopters as having 2xR22 and 2xR44 so if they were all up it would be busy...

Watch out for the windshear from the trees and hangars at CBN as well - that can be much worse than any downwash effects from an R22, worst when the wind is greater than 20 degrees off the runway direction.

FL (and our spy)

[Chocks Wahay]

Floppy Link PDG are very professional, and very good - watching them hover-taxying to within a few feet of the hanger is awesome.

Not in a Streak Shadow, I'm more your average spamcan type bloke.

The heli took off more or less as I flared, so I would imagine that would be maximum downwash. There was no warning of what he was doing, so I wasn't prepared for it. Just goes to show - just because a helicopter is 10-20m away from your touchdown point, and pointing straight towards you, never assume that he has seen you and will stay put.

Agree the upwind end would be ideal, however there's even less room there at Cumbernauld, so it could be messy if someone needed the full length. Certainly didn't see any heli's at that end while I was there.

Can't vouch for the 10 minutes, didn't really time them, but there was a lot of activity.

[Grainger]

CW:

The Northside grass at Cumbernauld is quite long and will absorb most of the R22/44 downwash before it gets to the runway.

Cumbernauld is one of those places - ironically because A/G is often unmanned - where we all keep a good lookout for each other so if you keep your r/t sharp then everyone will know where everyone else is and manage to avoid each other.

As for lifting as you are on finals - one reason for that might be so the pilot can turn and see you. Helis will always call before transitioning or crossing the active but they would have heard you call finals anyway. Personally I usually call "holding northside grass" just to avoid any doubt.

If you're not used to it, I can understand that seeeing helis operating on the northside grass could be disconcerting - best thing to do would be to drop in at Scotias and ask for a quick trial flight so you can see how it works. Never know, you might get converted !

[ ps: no I don't instruct or work for Scotia, but I do visit EGPG fairly often ]

[ 12 August 2001: Message edited by: Grainger ]

[Richard49]

If ever you decide to fly to Weston Airfield in Ireland - then definitely watch out - it's A/G Information - at times both circuits are in use and you will find Helicopters hovering alongside the runway! and someone back tracking just as you are on short final - it's alright once you get used to it, it's just a lot of people trying to use a limited space a bit daunting at first but it certainly reminds you to keep a sharp look out and that your safety is your own responsibility

[Grainger]

Don't forget, the RT is there to be used: as the landing aircraft YOU have right of way, so if you think someone - fixed wing or rotary - hasn't seen you, a firm RT call will get the message across.

Remember also that helis are more used to mixing it with fixed wing traffic than vice versa: although it may be an unusual situation for yourself as a visitor, you'll find that regular users of the airfield will be well aware of what is going on around them...

[Deeko01]

Thanx for the words about PDG, Floppy and Chocks, I was a crewman for them for 5 years based at cumbernauld and I can assure you they are very aware of the affect the downwash will cause to a light aeroplane/helicopter on the ground, like I said earlier it really shouldn't be a problem if everyone uses good airmanship.

I suggest if your worried why dont you speak to the PDG or Scotia, the Chief Training Captain is based at CBN for PDG and is he very concious of Flight Safety and if you think this is being compromised in any way then please dont hesitate to speak to him.

When I worked there we tried and still do to maintain a good working relationship between fixed wing and helicopter operators as it is a relatively small airfield as you know!

Happy landings! ;)